1. Field
The present invention relates to portable water sprinkler apparatus of the type which has an elevated sprinkler head for distributing water over tall foliage and for covering larger areas per sprinkler head than can be achieved with ground level sprinkler heads. The present invention further relates to systems for agricultural irrigation using the elevated, portable sprinkler apparatus.
2. State of the Art
There are various sprinklers used in residential and agricultural irrigation wherein the sprinkling action or projection of water is produced by passing the water through a nozzle, wherein the water is ejected from the nozzle as a coherent stream. The stream of water generally breaks up as it passes through the air, with water droplets falling from the stream over the entire trajectory of the ejected stream. In one type sprinkler, an oscillating impact member is used to physically break the stream of water so as to provide additional water distribution in the area adjacent to and relatively near the sprinkler. In addition, the impact member is also used to produce a force to rotate the nozzle about a generally vertical axis.
It has been recognized that by elevating the sprinkler nozzle above the level of the ground which is being irrigated, the area covered by a single sprinkler nozzle can be increased. Further, it has been recognized advantageous to raise the sprinkler nozzle above growing crops, shrubbery or other obstacles to allow the ejected stream of water to pass over the obstacles. Otherwise, the sprinkler has to be moved several times to avoid the obstacles and to avoid shadowing or dry spots caused by the obstacles.
Tripod stands have been suggested comprising a standpipe which extends vertically through the hub of the tripod stand. See, for example, U.S. Pat. No. 1,959,886, issued to Willard Wadsworth on May 22, 1934. Experience has shown that the tripod stands are generally unstable when a sprinkler head is used in which a stream of water is forcefully ejected laterally in one direction through a nozzle from the sprinkler head. Such sprinkler heads are generally adapted to rotate about a vertical axis with an impact device which interacts with the ejected stream of water to rotate the sprinkler head. One such commonly available sprinkler head is sold under the tradename "Rainbird" by Rainbird Sales Corporation of Glendora, Calif. Unfortunately, the reactive force of the ejected water stream from the sprinkler head acts with the movement are created by the height of the sprinkler stand to tip the stand over. The situation is aggravated if there is a breeze or wind which increases the tilting force on the stand
To alleviate the instability problem inherent with the elevated sprinkler stand, the stand can be weighted or made of a heavy construction. This, however, greatly reduces the usefulness of the stand as a portable apparatus. As shown in U.S. Pat. No. 2,694,600, issued to Albert E. Rickey on Nov. 16, 1954, a heavy, circular base member is provided, with the tripod supported permanently on the circular base member. Wheels were provided for moving the large and cumbersome stand from one place to another.
Heretofore, to the best of the present inventor's knowledge, there has been no suggestion of utilizing a vertical support stand for a water sprinkler head wherein the stand comprises a central support hub with a sprinkler head coupled thereto and further with at least five, flexible, elongate legs attached to the support hub such that the legs are equally spaced around the support hub and extend outwardly in an acute angle from the central, vertical axis through the support hub.